Multiline ternary chains don't instrument correctly

[chapati23]

Description

Both truffle compile (using global truffle) as well as yarn truffle compile (using local truffle) work. However, the second truffle compile that's running inside solidity-coverage throws an error during compilation and I don't understand how this could happen because it seems I'm using the same version everywhere. Is it an issue with the instrumentation?

Versions

macOS 10.13.3
node.js 9.4.0
truffle (global) 4.0.1 with solidity 0.4.18
truffle (local) 4.0.1 with solidity 0.4.18

The Error

This error occurs during the second compilation, if I understand solidity-coverage correctly, this means after instrumentation

smart-contracts/coverageEnv/contracts/Cov.sol:27:9: TypeError: Wrong argument count for function call: 2 arguments given but expected 1.
      : balances[_address]
        ^
Spanning multiple lines.

smart-contracts/coverageEnv/contracts/Cov.sol:25:81: TypeError: True expression's type tuple(tuple(),uint8) doesn't match false expression's type uint256.
uint256 _totalPerTokenUnclaimedConverted; (,_totalPerTokenUnclaimedConverted) = totalPerTokenPayout == 0
                                                                                ^

How To Reproduce

Here's a minimum contract to reproduce:

pragma solidity 0.4.18;

import "zeppelin-solidity/contracts/token/PausableToken.sol";

contract TestToken is PausableToken {
  uint256 public totalPerTokenPayout;
  mapping(address => uint256) public claimedPerTokenPayouts;

  function TestToken () public { }

  function currentPayout(address _address)
    public
    view
    returns (uint256)
  {
    uint256 _totalPerTokenUnclaimedConverted = totalPerTokenPayout == 0
      ? 0
      : balances[_address]
      .mul(totalPerTokenPayout.sub(claimedPerTokenPayouts[_address]))
      .div(1e18);

    return _totalPerTokenUnclaimedConverted;
  }
}

[cgewecke]

@chapati23 This is very likely an instrumentation bug. We try to capture branch data for ternary operators and you are using a relatively complex multiline / chained expression. If you have a chance, could you see if the error is resolved by restructuring the code in your example as a conventional if/else statement?

[chapati23]

Indeed. If I get rid of the ternary, the TypeError disappears.

[cgewecke]

Fixed for the nth time in #830